7 is a big improvement...
If you have vista, and qualify for one of the cheap upgrade options to 7, it might be worth it, but only if you're certain all of your apps are 7 compliant.
If you have XP, and a very recent machine (likely because you downgraded from Vista), with 2GB of RAM or more and a dual core, then going to 7 is worth it, though you'll likely have a lot of software to buy. If you have an older machine, wait until you get a new one.
There's still issues:
- control panels are an inconsitant nightmare, worse even than vista, but simply ignore that and launch the panels direct from the start menu and you'll never notice.
- Backup is still broken, but now worse as the image backups are also automatic. File recovery works, but not system recovery, unless the images are burned to DVD, but that's not an option unless you do them manually on your own. Images to disk or network locations are STILL broken (restore media can't find them even if you browse it to the right folder manually).
- lots of default settings are not the prefered settings
- Search still sux.
- changes to start menu basically force you to use search instead of browsing for an app as you're used to
- home folders are still screwed (why can't I move the WHOLE home directory, instead I have to move 15 seperate folders which takes 6 clicks each and i have to browse each time for the new location! OMFG!)
That said it is more stable, its definetly faster, it certainly looks better, the taskbar is an improvement (if marginal), networking is much improved, reinstalls are quick and painless (reinstalling XP now takes hours with so many patches and packs to install followed by dozens of apps and features included already in 7), media center is improved, and honestly, once you use it for a month or so it really is a nicer experience (it's no OS X, but it's clearly taking lessons from it).
Stop listening to the media, swap out your hard drive, install 7, and USE it, then you can bash it if you don't like it. Odds are you won't dislike it, other than typical "why did they move/change that" which you soon get over, and in some cases, realize that although it's not what you;re used to, it is better in many ways.